---web.php---
Route::get('/api/webhook/{val1?}/{val2?}/{val3?}', [AppHttpControllersXyzController::class, 'xprocess'])->name('xprocess');
---XyzController.php---
public function xprocess(Request $request, $val1=null, $val2=null, $val3=null)
{
$val1 = $request->query('val1');
$val2 = $request->query('val2');
$val3 = $request->query('val3');
//process variables etc...
}